Fix memory error in test_ucn.
unicode-escape decoder requires memory for result corresponding to input size.
Fixes test for issue #16335.
Fix memory error in test_ucn.
unicode-escape decoder requires memory for result corresponding to input size.
Fixes test for issue #16335.
Fix memory error in test_ucn.
unicode-escape decoder requires memory for result corresponding to input size.
Fixes test for issue #16335.